Many factors influence the perceived quality of a printed document or image. A central factor is the overall appearance of the image or other information recorded on the printed document. Another factor is the perceived quality of the receiver material upon which the image or document is printed. Images and documents that are printed using stiffer receiver media tend to be thicker and heavier and convey a greater sense of permanence, reliability and investment by the printer. Stiffer media are also suggestive of an intrinsic value of the printed image or document. Critical life documents, such as birth announcements, birth certificates, marriage certificates, college diplomas, business cards, post cards, photopaper, mounted photographs and the like, tend to be printed on stiffer, thicker stock paper.
Such stiffer stock receiver media are, typically, more difficult to print on than conventional stock media. For example, turning ratios that are perfectly acceptable and commonly in use in thermal, electrophotographic and ink jet printers, when used with more compliant, thinner receiver medium can stretch, damage, curl or bend such stiffer receiver media. Such effects tend to diminish the appearance of the printed image or document. Many conventional consumer and retail sheet fed and roll fed digital printers are incapable of using popular types of stiffer receiver media.
Professional and commercial printing systems permit adjustments when stiffer types of receiver media are used. However, such adjustments are not typically available in retail and consumer level devices. When consumers wish to obtain printed images on stiffer types of receiver media, they typically seek out a commercial printer. It is also known to print using a more compliant receiver medium and to then mount the more compliant receiver medium on a separate stiffer or thicker and less compliant picture mounting board. Construction paper, cardboard, and foam core type boards have been employed for such use. However, this adds significant costs to the process because it involves additional materials, equipment and secondary operations.
The use of stiffer and/or thicker receiver medium can conflict with a wide variety of other considerations at the consumer and/or retail printing level. For instance, consumers have shown a preference for stand alone portable printers such as the EasyShare® line of photo printers sold by the Eastman Kodak Company, Rochester, N.Y., USA. An important consideration with such printers is that the receiver medium must be carried with the printer to the destination and that there must be a sufficient supply of receiver medium to justify bringing the printer to the destination. However, the internal storage capacity of the printer is limited in size. When stiffer receiver media are used that are also thicker than conventional receiver media, the storage capacity available in such printers is effectively reduced. This requires that such media are taken along separately which can be inconvenient.
U.S. Pat. No. 7,122,232 describes a print medium that is expandable and collapsible comprising two sheets separated by at least one collapsible brace. While such medium is designed to enable the medium to be sufficiently thin and flexible for transport through a printer when in a collapsed mode and to provide a substantially rigid structure when the collapsible brace is in an expanded position, such medium is relatively mechanically complex.
Another consideration at the consumer level is that the use of stiffer/thicker receiver medium is expensive, because such thicker or stiffer receiver medium is often solidly filled with relatively expensive materials such as pulp, fiber or polymers. Consumers often prefer to use such thicker/stiffer receiver medium only for special print jobs and reserve thinner receiver medium for other print jobs.
What is desired is a digital printer and printing system and medium that can provide printed images and documents having a desired thickness or stiffness without requiring that the consumer make complex adjustments to the operation of a printer and without imposing the need for complex mechanical systems or the financial, weight and volume difficulties typically associated with thick/stiff receiver media.
U.S. Pat. No. 6,937,358, entitled “Printable Substrate Having Controllable Thickness and Method for Making and Using Same” filed by Sullivan et al. on Nov. 13, 2001, describes a method and an apparatus for controlling the volume of a printable substrate after an image is created thereon, and is more particularly directed to the production and use of a calenderizeable substrate in which a final thickness of the substrate may be adjusted to reduce the thickness of the substrate. This is done to facilitate transport and/or storage of the document after printing. The system employed for the process includes a pair of compression rollers wherein the nip force therebetween may be adjusted. In one example, Sullivan et al. provides a method for reducing a thickness of a compressible substrate bearing an image. A compressive force is applied to the substrate to compress the substrate to a thickness less than an initial thickness. The compressive force selected to preclude the substrate returning to the initial thickness after removal of the compressive force therefrom: heat is concurrently applied to the substrate. This does not solve the above described problems relating to printing with thicker/stiffer media or enhancing consumer's quality perception and ease of use and portability.
Papers having thermally expansive materials such as hollow expandable spheres or foaming agents that contain materials that can be heated during manufacture of the paper to expand and thereby create lower weight but thicker materials are well known. Such papers are described for uses such as the formulation of packaging and containers. (See, for example, U.S. Pat. Nos. 3,293,114; 3,556,934; 3,779,951; and 3,941,634). However, approaches described therein address challenges that arise in paper manufacture, and it is assumed in these patents that such paper is fabricated with micro-beads so that as fabricated the receiver medium is thickened before printing.
Papers or other media having micro-spheres have also been used to allow relief patterns to be formed in an image after printing. See, for example, U.S. Pat. Nos. 4,268,615; 5,125,996; 5,325,781; and 5,639,540 and JP 08-224957. These references disclose, generally, the use of receiver medium having expandable micro-beads that can be expanded to enable the pattern-wise creation of relief patterns.
There remains a need for a printer, printing system, printing method and receiver medium that enable thin receiver material to be loaded into the system and that processes the receiver medium such that the output stiffness and/or thickness of the receiver medium is adjusted, especially increased.